Antimicrobial activity of Phoma sp. URM 7221: An endophyte from Schinus terebinthifolius Raddi (Anacardiaceae)

Abstract

The discovery of new metabolites potentially bioactive against pathogenic microorganisms, mainly multidrug resistant, has aroused interest in endophytic fungi. The plant-assocd. microorganisms have been an important source for development of new compds. of biotechnol. interest. This study aimed to investigate the antibacterial capacity of the endophytic fungus, Phoma sp. URM 7221 isolated from the medicinal plant Schinus terebinthifolius against human-pathogenic bacteria. An endophyte was isolated from S. terebinthifolius leaves. Phoma herbarum URM7221 was characterized morphol. and on the basis of ITS rDNA sequence. Primary antimicrobial activity was evaluated using the agar diffusion method and fermn. in liq. medium. Six different solvents were used to ext. the active metabolites from fungal biomass and metabolic liq. An antimicrobial activity test from the ext. was carried out using a disk diffusion method with the endophytic ext. contg. the best antibacterial activity. Two tests were performed: Min. inhibitory concn. (MIC) and min. bactericidal concn. (MBC). Partially purified secondary metabolite exts. were analyzed by thin layer chromatog. (TLC). Liq. metabolically bioactive compds. extd. with petroleum ether revealed a MIC of 25 and 500 μg.mL-1 against S. aureus and MRSA, resp. Ether and methanol exts. were assessed by chem. analyses and contained phenolic compds., triterpenes, steroids, reducing sugars, mono- and sesquiterpenes. The thin layer chromatog. assay showed the activity of different antimicrobial compds. produced by Phoma sp. URM7221. This endophyte (URM7221) could be efficiently used for prodn. of bioactive metabolites against pathogenic microorganisms, with significant biotechnol. potential. [on SciFinder(R)]